1. The field of art to which the invention pertains includes the art of measuring and testing as related to food thermometer apparatus.
2. Oven cooking food thermometers are recognized as a very useful kitchen appliance and are, therefore, widely employed both commercially and domestically. By inserting the temperature sensitive probe of the thermometer into the uncooked food, usually meat to be roasted, the thermometer will sense the internal food temperature and over a period of time in the oven will provide an indication of cooking completion. Most oven cooking thermometers are of the visual type enabling external temperature readout reflecting the internal food temperature which can then be correlated to the state of cooking completion. Exemplifying thermometers of this type are the disclosures of U.S. Pat. Nos. 2,276,178; 3,626,897 and 3,820,499. The obvious deficiency of such thermometers is the requirement for frequent checking of the readout temperature to avoid inadvertent overcooking. The latter, of course, can represent a problem of some magnitude with a particularly busy chef. A food thermometer for producing an audible alarm at preset food temperatures is disclosed in U.S. Pat. No. 3,778,798. While overcoming the deficiency of the visual type thermometer, the latter represents a relatively sophisticated and complex unit and is generally available only as a permanent part of the oven with which it is supplied.
Despite recognition of the foregoing, it has not been known heretofore how to produce a portable cooking thermometer of the audible alarm type that is presettable yet sufficiently economical to manufacture as to be affordable as a separate accessory item for conventional domestic use.